Ophthalmic surgical device for accessing tissue and for performing a capsulotomy

ABSTRACT

A surgical device and procedure are provided for smoothly and easily accessing tissue to perform microsurgery, including a capsulotomy of a lens capsule of an eye. The device includes a handpiece with a tip for insertion into an incision in the cornea of the eye. A sliding element is disposed within the handpiece and a suction cup is mounted to the sliding element. The sliding element can be translated to move the suction cup into and out of the handpiece. A compression mechanism associated with the suction cup and the handpiece compresses the suction cup for deployment through the tip of the handpiece. The suction cup can expand inside the anterior chamber into a cutting position on the lens capsule. A cutting element mounted to the suction cup is used to cut a portion of the lens capsule and to remove the portion from the eye.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/702,305 filed on Dec. 6, 2012, which is a national phase applicationof PCT/US10/37627, filed on Jun. 7, 2010, the entire disclosures ofwhich are hereby incorporated by reference herein, including anyappendices or attachments thereof, in their entirety for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under Grant Number1R43NS067701-01 awarded by the National Institutes of Health. Thegovernment has certain rights in the invention.

BACKGROUND

This invention pertains in general to microsurgery of tissue, and morespecifically to procedures and devices for accessing a tissue throughanother tissue layer, to cut or otherwise manipulate that tissue. Forexample, the procedures and devices can be used to deliver an ophthalmicsurgical device through the cornea to the anterior lens capsule membranein the anterior chamber of an eye.

Lens cataract is the leading cause of blindness worldwide and surgicaltreatment by cataract removal is the treatment of choice. A cataract isa clouding that develops in the lens of the eye or in its envelope. Thecreation of areas of opacity in the lens obstructs the passage of light.The lens of the eye is supposed to be transparent. If the lens developsopaque areas, as in a cataract, the lens must be surgically removed. Ifno lens is present in the eye, heavy corrective glasses are required tofocus an image on the retina. The lens, however, can be replaced with anartificial interocular lens (IOL) to provide better vision aftercataract removal. There may also be other reasons to replace a lens thatis not serving its functions appropriately.

The removal of the lens for replacement with an IOL is a surgicalprocedure that requires substantial precision. The lens is completelyenclosed by a membrane called the lens capsule, so the surgeon mustfirst cut through the capsule to access the lens. It is important to cutthe capsule in just the right way. If the lens capsule has been cutcorrectly, and not damaged during the cataract removal, then it can beused to hold an IOL. The implantation of an IOL requires the creation ofan opening in the lens capsule that is precisely centered, sized, andshaped for implant stability and for optimal IOL function. The matchingof the lens capsule opening size to the peripheral margins of the IOL iscritical. The goal of the surgeon is to create a perfectly circular(e.g., 5.5+/−0.1 mm diameter) hole in the capsule, centered exactly onthe optical axis of the eye, with no tears or defects in the edge of thehole. Tears or defects on the edge of the hole make the capsule veryweak and vulnerable to losing the ability to hold the IOL properly.Different IOL designs may require a different diameter for the hole(e.g., ranging from 4.5+/−0.1 mm to 5.75+/−0.1 mm), but whatever theprescribed diameter is, the accuracy of the surgeon in actuallyachieving it is very important for proper outcome of the cataractsurgery. This is especially true of IOLs intended to perform complexoptical and focusing functions.

Creating an opening in the lens capsule with this required level ofprecision is a difficult task for a surgeon controlling and guidingconventional handheld cutting instruments and attempting to trace aprecise circular route on the lens capsule. Currently, to perform acapsulotomy (the creation of an opening in the lens capsule), thesurgeon typically manually creates a small tear in the anterior regionof the lens capsule. With great caution, the surgeon then uses a smallneedle-like cystotome and/or forceps to try to extend the edge of thetear so as to follow a circular path of the specified diameter andcentered on the optic axis of the eye. In practice, it often happensthat the hole does not end up circular, or the correct diameter, orcentered on the optic axis. There can also be radial tears in the edgeof the hole that greatly weaken the capsule. As a result of any of theseerrors, the capsule may not be able to hold the IOL properly, andoptimal visual outcome cannot be achieved.

In addition to the difficulties faced by the surgeon in accessing thelens by performing a precise capsulotomy of the lens capsule, thesurgeon must also be able to access the lens capsule itself. The lens ispositioned in the anterior chamber of the eye. To access the lenscapsule, the surgeon must create an incision in the cornea and carefullyinsert the capsulotomy instruments through this incision. The samerequirement exists in a number of microsurgery procedures in which anincision in a first layer of tissue must be passed through before asecond layer of tissue, behind or beneath that first layer, can beaccessed. For the surgeon to maneuver the microsurgery instrumentsthrough the corneal incision, the incision must be of sufficient size toaccommodate these instruments. However, the larger the incision, thegreater the risk of infection, of corneal distortion, and of othercomplications. Microsurgery instruments commonly are not compact enoughor are not sufficiently streamlined, making it difficult for the surgeonto minimize the incision size or possibly risking tears or other damageat the incision site. Cutting elements or other sharp components aresometimes exposed during insertion, requiring the surgeon to be veryprecise and creating further risk of collateral damage to tissue wheninserting the instrument through the incision. Further, this insertionoften requires multiple steps and sometimes complex maneuvering ofinstruments by the surgeon, leaving little room for error. Onceinserted, instruments are often not easily manipulated and the surgeonmay be forced to handle and move multiple separate pieces in a smallspace. Any of these problems can make it very difficult for a surgeon toaccess a second layer of tissue behind a first layer, particularly whenthe second layer is tissue in a very small area, such as within the eye.

Given the drawbacks of existing treatment devices/procedures foraccessing tissue, such as the lens capsule, to perform surgery, improvedtechniques and devices for performing microsurgery are needed.

SUMMARY

Embodiments of the invention include devices and methods for accessing alens capsule through a cornea of an eye, for performing a capsulotomy inthe eye. The lens capsulotomy device includes a handpiece having a tipdesigned for insertion into an incision in the cornea of the eye. Thehandpiece has a sliding element disposed therein and a suction cup ismounted to the sliding element for movement into and out of thehandpiece. A cutting element is mounted to the suction cup. Acompression mechanism associated with the suction cup and the handpiececompresses the suction cup for deployment through the tip. Once the tipof the device is inserted through the corneal incision, the compressedsuction cup plus cutting element can be translated in one smoothmovement out through the tip of the device and into proximity to thelens capsule. The suction cup plus cutting element expands inside theanterior chamber for creating an opening in the lens capsule.

In operation, the surgeon compresses the suction cup plus cuttingelement (e.g., by manipulating a knob or other mechanism on thehandpiece and the surgeon moves the tip of the capsulotomy devicethrough an incision in the cornea of the eye (though the tip of thecapsulotomy device could also be inserted into the incision beforecompression of the suction cup). The compressed suction cup is deployedout through the tip of the handpiece into the anterior chamber and thesuction cup expands inside the anterior chamber into a cutting positionon the lens capsule. Suction can be applied to the suction cup forsecuring the cup to the lens capsule and for pulling the tissue of thelens capsule against the cutting element of the suction cup to cut aportion of the lens capsule (e.g., a circular portion). The suction canthen be reduced for releasing the suction cup from the lens capsulewhile still retaining the excised piece of tissue with the suction cupduring device removal. The device is withdrawn through the incision andremoved from the eye. Cataract or other lens surgery can then beperformed on the eye (i.e., the lens can then be removed by normalmethods of cataract surgery).

Other embodiments include devices and procedures for accessing a secondlayer of tissue behind a first layer of tissue for performingmicrosurgery or therapeutic work on the second layer, where the tissueis not limited to lens capsule or eye tissue. The surgical deviceincludes a handpiece having a tip for insertion through an incision inthe first layer of tissue and a sliding element disposed within thehandpiece. A foldable structure (e.g., a suction cup or othercollapsible device) is mounted to the sliding element for movement intoand out of the handpiece. Compression arms, for compressing the foldablestructure, are positioned at sides of the foldable structure and areassociated with the handpiece. A manipulation mechanism manipulates thecompression arms to compress the foldable structure for deployment outthrough the tip of the handpiece past the first layer of tissue. Oncedeployed, the foldable structure expands into an operational position onthe second layer of tissue. An operational element associated with thefoldable structure is used to engage in microsurgery or therapeutic workon the second layer of tissue. In some embodiments, the operationalelement is a cutting element used to cut a portion of the second layerof tissue.

In operation, the surgeon applies pressure to sides of a foldablestructure inside the handpiece of the device (e.g., by pressing a knobor other handpiece mechanism) to compress the foldable structure. Thesurgeon accesses a second layer of tissue behind a first layer of tissueby moving the tip of the microsurgical device through an incision in thefirst layer of tissue (though the tip of the device could also beinserted into the incision before compression of the foldablestructure). The procedure further includes translating the slidingelement within the handpiece toward the tip to deploy the compressedfoldable structure out through the tip of the handpiece past the firstlayer of tissue. Once deployed, the foldable structure expands into anoperational configuration on the second layer of tissue. The surgeonthen engages in microsurgery or therapeutic work on the second layer oftissue. In some embodiments, the microsurgery or therapeutic workperformed includes cutting of a portion of the second layer of tissue(e.g., with a cutting element associated with the foldable structure).

These techniques enable a surgeon to access and perform minimallyinvasive microsurgery on tissue, such as the lens capsule. The surgeoncan reversibly access the lens capsule via a very small incision, sincethe foldable structure/suction cup with cutting element, which is largerin diameter (e.g., about 5 mm to 7.5 mm) than the length of the incision(e.g., about 2 mm to 3 mm in length), can be compressed within thehandpiece to a small size and smoothly deployed through the tip of thehandpiece. This minimizes infection and corneal distortion riskscompared with previous access techniques. The cutting element isprotected within the device during insertion of the device into theincision, avoiding collateral tissue damage and damage to the cuttingelement or whatever element is being deployed using the device. Only onesmooth suction cup deployment motion, via the compact and streamlineddevice, is required to access the lens capsule, reducing the amount ofmaneuvering required by the surgeon to access the tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of the microsurgery/capsulotomy devicewith the suction cup deployed, according to an embodiment of theinvention.

FIG. 2 is a top perspective view of the microsurgery/capsulotomy devicein use in the anterior chamber of the eye, according to an embodiment ofthe invention.

FIG. 3 is a top perspective view of the microsurgery/capsulotomy devicewith the suction cup stowed inside, according to an embodiment of theinvention.

FIG. 4 is an uncovered top perspective view of themicrosurgery/capsulotomy device with the suction cup stowed inside,according to an embodiment of the invention.

FIG. 5 is an uncovered top view of the microsurgery/capsulotomy devicewith the suction cup stowed inside, according to an embodiment of theinvention.

FIG. 6 is an uncovered top view of the microsurgery/capsulotomy devicewith the suction cup compressed, according to an embodiment of theinvention.

FIG. 7 is an uncovered top view of the microsurgery/capsulotomy devicewith the suction cup compressed and translated into the tip, accordingto an embodiment of the invention.

FIG. 8 is an uncovered top view of the microsurgery/capsulotomy devicewith the suction cup deployed, according to an embodiment of theinvention.

FIG. 9 is a partially exploded perspective view of themicrosurgery/capsulotomy device with the suction cup deployed, accordingto an embodiment of the invention.

FIG. 10 is an exploded top perspective view of themicrosurgery/capsulotomy device with internal components also shown inexploded perspective view, according to an embodiment of the invention.

FIG. 11 is an exploded perspective view of the compression arms and partof the handpiece, according to an embodiment of the invention.

FIG. 12 is an exploded perspective view of the sliding element andcompression arms, according to an embodiment of the invention.

FIG. 13 is a top perspective view of the cutting element, according toan embodiment of the invention.

FIG. 14 is a top perspective view of the cutting element with tethersmelted (or made without tethers), according to an embodiment of theinvention.

FIG. 15 is a bottom perspective view of the suction cup, according to anembodiment of the invention.

FIG. 16 is a cross-sectional bottom perspective view of the suction cup,according to an embodiment of the invention.

FIG. 17 is a cross-sectional side view of another design of the suctioncup, according to an embodiment of the invention.

FIG. 18 is a top perspective view of another design of the cuttingelement, according to an embodiment of the invention.

FIG. 19 is an exploded top perspective view of another design of suctioncup and the cutting element involving dual tubing, according to anembodiment of the invention.

FIG. 20 is a top perspective view of another design of themicrosurgery/capsulotomy device with the suction cup stowed, accordingto an embodiment of the invention.

FIG. 21 is a bottom perspective view of another design of themicrosurgery/capsulotomy device with the suction cup deployed, accordingto an embodiment of the invention.

FIG. 22 is a top perspective view of another design of themicrosurgery/capsulotomy device with the suction cup deployed, accordingto an embodiment of the invention.

FIG. 23 is a flow chart illustrating preparatory steps for themicrosurgery/capsulotomy procedure, according to an embodiment of theinvention.

FIG. 24 is a flow chart illustrating steps for themicrosurgery/capsulotomy procedure, according to an embodiment of theinvention.

FIG. 25 is a flow chart illustrating a continuation of the steps for themicrosurgery/capsulotomy procedure, according to an embodiment of theinvention.

The figures depict an embodiment of the present invention for purposesof illustration only. One skilled in the art will readily recognize fromthe following description that alternative embodiments of the structuresand methods illustrated herein may be employed without departing fromthe principles of the invention described herein.

DETAILED DESCRIPTION

Microsurgery/Capsulotomy Device

Embodiments of the invention are described herein in the context of alens capsule surgery in which a portion of the anterior surface of alens capsule is cut. This technique may be used for performing atreatment for cataracts in which all or a portion of a lens locatedwithin the lens capsule is removed from the eye. The procedure may alsobe used to create an access hole in the lens capsule through which toimplant an artificial lens (e.g., an intraocular lens, or IOL) withinthe lens capsule. Though often described herein in terms of performinglens capsule surgery, the devices and procedures are not limited to lenscapsule surgery, but can also be useful in other treatments of the eye,such as a corneal surgery, treatments for glaucoma, microfenestration ofthe optic nerve, surgeries involving decemet's membrane, among others.Furthermore, the devices and procedures may also be useful in thedelivery of pharmacologic, biologic, and chemical entities andtherapeutics. The devices and procedures can also be used to deliverfluids in addition to suction, and the delivery can be specificallylocalized (e.g., by the suction cup) limiting exposure only to desiredtissues. In addition, the devices and procedures may be useful forindustrial applications or performing other medical procedures outsideof the eye, such as procedures involving excision of delicate membranesor tissue structures, fenestration of brain dura, and others. Thedevices and procedures can also be used outside of the body (in vitro),on tissue excised and separate from the body, for industrialapplications, etc. In these other types of applications, the proceduresand devices function generally in the same manner as described regardingthe lens capsule surgery, though the components may be differentlyarranged, sized, shaped to accommodate different tissue.

FIG. 1 is a top perspective view of the microsurgery/capsulotomy device1 with the suction cup/foldable structure 2 deployed, according to anembodiment of the invention. The device 1 is designed for accessing asecond layer of tissue (e.g., lens capsule) behind a first layer oftissue (e.g., cornea) for performing microsurgery. The device 1 includesa handpiece 5 or structure with a housing that can be manipulated by thesurgeon for performing the surgical procedure (e.g., to perform thecapsulotomy step of lens surgery). The handpiece includes a tip 3 forinsertion through an incision in the first layer of tissue (e.g., anincision in the cornea of the eye). The tip 3 is narrow and streamlinedin shape so it can easily be slipped into the incision in the tissuewithout tearing the incision or otherwise damaging the tissue. The tip 3includes an opening 14 through which the foldable structure or suctioncup 2, connected at the end of a stem 19, can be deployed. The handpiece5 is shown in FIG. 1 as a long, generally cylindrical-shaped structure,though the handpiece 5 can take on a variety of shapes and forms.

The structure deployed through the tip of the handpiece 5 can be asuction cup 2 as show in FIG. 1. However, it can also be any other typeof foldable, collapsible, or compressible structure that can be folded.For example, the structure 2 could be another shape required forfunctioning with a particular tissue type. The device 1 provides amechanism of delivering a foldable structure of any type or shapethrough a small opening by allowing for orderly folding of this device.Thus, where “suction cup” is referred throughout this description, itcan also be replaced with another type of foldable device. Further, thesuction cup 2 shown in FIG. 1 is designed to be folded predominantlyalong one axis, and specifically it is predominantly compressedlaterally, while still remaining flat inside the device 1 (as will bedescribed in more detail below). However, different suction cup orfolding structure types may be folded predominantly along a differentaxis or otherwise compressed for deployment to various tissue types. Insome embodiments, the suction cup is folded only along one axis, whilein other embodiments the suction cup is folded along more than one axis.

The device 1 further includes a manipulation mechanism that comprises aknob 8 connected via a slot 9 in the housing of the handpiece 5 to aslider/sliding element 7 that can be moved forwards and backwards by thesurgeon pushing on the knob 8. A portion of the slider 7 is shown at theend of the handpiece 5 opposite the tip 3. The surgeon can manipulatethe knob 8 back and forth along the slot 9. The slot 9 in the housingcan restrict the movement of the slider 7 to a maximum forward positionand a maximum rear position, as illustrated in FIG. 1. In someembodiments, a storage latch 12 holds the slider 7 in its shippingposition prior to use. Manipulation mechanisms other than a knob 8 canalso be used to move components within the device, such as a lever,button that is depressed, a switch, a rotatable knob, a flap, and soforth.

In use, the handpiece 5 can be plugged into a hose (e.g., via hose barb10) that leads to a controlling system that provides air flow andsuction. The handpiece 5 can also be plugged into electrical wires(e.g., at electrical connectors 11) that lead to a controlling systemthat provides electrical current and makes electrical measurements. Thedevice 1 can further include a lumen within the slider 7 to allowfluidic transport from the hose barb 10 to the suction cup 2. Theelectrical connectors 11 can also connect to the electrical circuitwithin a lumen of the slider 7. A lubrication hole 4 allows for theapplication of a suitable lubricant, including viscoelastic (which isnormally used inside the eye during cataract surgery) to the suction cup2 and the passageway through which it will slide. In some embodiments,all or a portion of the device 1 disposable.

FIG. 2 is a top perspective view of the microsurgery/capsulotomy device1 in use in the anterior chamber of the eye 100, according to anembodiment of the invention. The parts of the eye 100 illustrated inFIG. 2 include the sclera 102, the cornea 101, the iris 103 and the lenscapsule 104. The device 1 illustrated in FIG. 2 is being used by anophthalmic surgeon to perform a capsulotomy, which is one of the stepsthat is typically performed in cataract surgery. The capsule 104 is atransparent membrane that encapsulates the lens of the eye 100. In FIG.2, the surgeon has made an incision 105 through the cornea 101. Theinsertion tip 3 of the device 1 has a narrowly-shaped leading edge (13,see FIG. 3) to mechanically find the corneal incision 105 and enter it.In FIG. 2, the tip 3 of the device 1 has already been inserted throughthe incision 105 in the cornea 101, and the suction cup 2 and stem 19have been pushed through the lumen (14, see FIG. 3) of the insertion tip3. When the system applies suction via the hose barb 10, the lenscapsule is forcibly held against the suction cup 2 and against thecutting element (shown in FIGS. 13, 14, and 18) contained therein.

A circular hole is cut in the anterior capsule 104 so that the lens canbe removed, and the IOL can be inserted. In some embodiments, thecircular opening in the capsule 104 or other tissue is approximately 5mm to 7.5 mm in diameter. However, other diameter openings can becreated with other embodiments, as desired for various surgicalprocedures (e.g., 1 mm, 2 mm, 3 mm, 4 mm, 8 mm, 9 mm, 10 mm, 15 mm, 20mm, and so forth). The circular patch of excised membrane can be heldwithin the suction cup 2 via suction and removed from the eye 100 alongwith the device 1. Once the device 1 is removed from the eye 100, theexcised tissue can be discarded. The rest of the capsular bag can remainundamaged so that it will have the structural integrity needed to holdthe IOL.

In some embodiments, the device 1 does not include a cutting element. Inthese embodiments, the device 1 can include one or more otheroperational elements for therapeutic work. For example, the device 1could include a tissue manipulation mechanism for grasping or otherwisemanipulating the tissue. As another example, the device 1 could includea mechanism for cauterizing, stretching, adjusting, stabilizing,providing fluids to, or performing other actions on tissue.

FIG. 3 is a top perspective view of the microsurgery/capsulotomy device1 in a stowed configuration with the suction cup 2 stowed inside,according to an embodiment of the invention. In some embodiments, thedevice 1 is shipped to the customer in this retracted configuration toprotect the suction cup 2 during shipping. The knob 8 is at the oppositeend of slot 9 toward the proximal end of the device 1 (as compared toFIG. 1 which illustrates the knob 8 at the distal end of the slot 9 whenthe suction cup 2 is extended from the tip 3). The storage latch 12 isengaged with a detent (22, FIG. 5) in the slider 7. The storage latch 12is designed to prevent unintended movement (e.g., during shipping), butto release under the application of intended force above a predeterminedthreshold. FIG. 3 also illustrates the leading edge 13 of the insertiontip 3 that is inserted through an incision in the tissue and the lumen14 of the insertion tip 3 through which the suction cup 2 can pass intoand out of the device 1.

FIG. 4 is an uncovered top perspective view of themicrosurgery/capsulotomy of the housing lower half 5A of handpiece 5 ofthe device 1 with the suction cup 2 stowed inside, according to anembodiment of the invention. The suction cup 2 is mounted via the stem19 to the slider 7 within the handpiece 5 for movement into and out ofthe handpiece 5. The slider 7, which was visible at the proximal end ofthe handpiece 5 opposite the suction cup 2 in FIGS. 1 and 3, is visiblein FIG. 4 within the housing of the handpiece 5. FIG. 4 also shows theknob 8 attached to the slider 7 (which is attached through the slot 9 inthe housing of the handpiece 5, as shown in FIGS. 1 and 3). The surgeoncan apply force to the knob 8 to slide it distally along the slot 9 totranslate the slider 7 distally within the handpiece 5. This slides thesuction cup 2 out through the tip 3 for positioning against the secondlayer of tissue within the first layer (e.g., against the lens capsulewithin the anterior chamber).

FIG. 4 also illustrates a portion of the compression mechanismassociated with the suction cup 2 and the handpiece 5. In the design ofdevice 1, the mechanism includes two compression arms 15 mounted to anarm base 21 (shown in FIG. 5) that is designed to translate relative tothe handpiece 5 and the slider 7. The compression mechanism alsoincludes latching arms 18 (shown more clearly in FIG. 6) that surroundthe location at which the knob 8 attaches to the slider 7. Thecompression mechanism is used to compress the suction cup 2 to a smallercross section between the tips 16 of the compression arms 15, so thatthe suction cup 2 can be deployed through the tip 3 of the handpiece 5once the tip 3 is inserted into the incision in the tissue. Since thesuction cup 2 is compressed, it can easily fit through the tip withouttearing or otherwise causing damage to the incision. The tips 16 of thecompression arms 15 are moved toward each other to compress the suctioncup 2 when they are translated distally within the device 1 and againstthe closing ramps 17 on the inside of the housing sidewalls.

FIG. 5 is an uncovered top view of the entire microsurgery/capsulotomydevice 1 with the suction cup 2 stowed inside, according to anembodiment of the invention. The compression mechanism, which is made upof the arm base 21, compression arms 15, and latching arms 18, is moreclearly visible in FIG. 5. In the design of FIG. 5, the arm base 21 ispositioned around the slider 7 for translation along the slider 7,though the arm base can be designed in other ways so that it is slidablerelative to the slider 7 (e.g., the arm base could be connected to theslider 7, but slidable within a slot in the slider 7, etc.). Thecompression arms 15 are positioned at the sides of the suction cup 2 andare mounted to the arm base 21. In the stowed position of FIG. 5, thearms 15 are separated and not touching the suction cup 2, and the knob 8is positioned at a proximal-most position within the latching arms 18 ofthe compression mechanism. FIG. 5 further illustrates the arm flexure 20at which the arms 15 bend to bring the arm tips 16 together to compressthe suction cup 2. FIG. 5 also shows the detent 22 in the slider 7 withwhich the storage latch 12 is engaged in the stowed position for safeshipping of the device 1. Both electrical connectors 11A and 11B arevisible in FIG. 5 for providing the electrical current to the cuttingelement of the suction cup 2 (where the cutting element is an electricalelement).

FIG. 6 is an uncovered top view of the microsurgery/capsulotomy device 1with the suction cup compressed 2B, according to an embodiment of theinvention. When an outside force is applied to move the knob 8, itslides along the slot 9 on the outside of the handpiece 5 and withinlatching arms 18 on the inside. FIG. 6 illustrates the latch boss 27,which is the mounting socket via which the knob 8 attaches to the slider7. The protruding latch bosses 27 on both the top and bottom surfaces ofthe slider 7 (shown only on the top surface in FIG. slide within thelatching arms 18 from a position at the proximal end of the latchingarms 18 (close to the arm base 21) to the distal end of the latchingarms 18 (toward the insertion tip 3). This translation of the knob 8(which moves the latch boss 27 within the latching arms 18) moves boththe slider 7 (including the suction cup 2) and the compression mechanismdistally. The arms 15 slide distally within the handpiece 5 until thetips 16 of the arms 15 contact the beginning 24 of the closing ramp 17.The ramp 17 presses the tips 16 of the arms 15 inward toward each otherto compress the suction cup 2. As the arms 15 continue to move distally,the tips 16 slide along the ramp 17 and are further pressed inward untilthey reach the end 23 of the closing ramp 17 where the suction cup 2 isfully compressed. The arm base 21 contacts one or more arm stops 26(e.g., molded into the top and bottom housing of the handpiece 5), whichprevent the compression mechanism from moving any further within thedevice 1.

As the suction cup 2 and arm tips advance together, the convergingsurfaces of the ramps 17 force the arms 15 towards each other (e.g.,like a tweezer) by a predetermined amount such that the suction cup 2 iscompressed to the desired width. Thus, there is no, or limited,frictional drag on the elastomeric suction cup 2. If the suction cup 2were to slide directly against the converging sidewalls, the frictioncould deform it rearwards and prevent the proper lateral compression.The use of intervening rigid tweezer-type tips 16 between the convergingsidewalls and the suction cup 2 enables pure lateral compression.

FIG. 7 is an uncovered top view of the microsurgery/capsulotomy device 1with the suction cup compressed 2B and translated into the tip 3,according to an embodiment of the invention. FIG. 7 illustrates thedevice 1 after the arm latches 18 have been forced to deflect andrelease their grip on the latch bosses 27. At this point, the knob 8 canstill be slid further along the slot 9 to translate the slider 7 furtherdistally, though the compression mechanism cannot move further distallydue to the arm base 21 having contacted the arm stops 26. The latchingarms 18 include an opening at the distal end through which the latchboss 27 (connected to the knob 8, not shown here) can move once the arms15 have reached the end of their translation range. The latch boss 27can move through the opening to continue translation of the slider 7 asthe suction cup 2 is deployed into the tip 3. It is at this point, aftersuction cup 2 compression and movement to the tip 3, that the surgeonwould typically insert the tip 3 through the corneal incision.

FIG. 8 is an uncovered top view of the microsurgery/capsulotomy device 1with the suction cup 2 deployed, according to an embodiment of theinvention. In this Figure, the elastomeric suction cup 2 has been fullydeployed and has expanded back to the prior shape it had when stowed.The slider 7 has been translated distally. The proximal-most end of theslider 7, which is wider than the rest of the slider 7, has contactedthe arm base 21. Thus, the suction cup 2 can be translated no further.The knob 8 is also shown fully translated to the distal end of slot 9.

FIG. 9 is a partially exploded perspective view of themicrosurgery/capsulotomy device 1 with the suction cup 2 deployed,according to an embodiment of the invention. This view shows the variouscomponents of the device 1 in a deployed state and illustrates both theupper 5B and lower 5A halves of the housing of handpiece 5. The latchboss 27 has been translated distally, out of the latching arms 18 andthe knob 8 as been translated to the distal end of the slot 9. Theslider 7 has been translated distally until it contacted the arm base21. The bottom housing 5A with the slider 7 and compression mechanismremoved is also visible. Groove 28 in the bottom housing 5A allowspassage of the latch boss 27 on that side of the device 1. The arm stops26 in the bottom housing 5A, which prevent further translation of thearm base 21 once the suction cup 2 is compressed fully, are also visiblein FIG. 9. The arm bend locations 20 are further more clearly visible inFIG. 9.

FIG. 10 is a further exploded top perspective view of themicrosurgery/capsulotomy device 1 with internal components also shownseparated, according to an embodiment of the invention. In this Figure,the slider 7 and compression mechanism are also separated from eachother. In this embodiment, the slider 7 has a bottom half 7A and a tophalf 7B with fluidic suction lumen 31 and trenches 29, 30 to containelectrical conductors (e.g., wires, not shown). The suction cup 2 plusstem 19 are shown separated from the slider 7 (though the suction cup 2,stem 19, and slider 7 could be a single piece) and the electrical 11 andsuction 10 components are shown detached from the device 1. Theelectrical pins 11 connect to trenches 29, 30 in which electrical wirescan be contained. The hose connection 10 connects to the fluidic suctionlumen 31 for delivering suction to the suction cup 2.

FIG. 11 is an exploded perspective view of the compression arms and partof the handpiece, according to an embodiment of the invention. FIG. 11shows a view of the housing and compression mechanism components tobetter reveal their features. Pegs 34 in the upper housing 5B engageholes 35 of the lower housing 5A to facilitate assembly. The protrudingstorage latch feature 12 engages the detent (22, FIG. 12) in the slider7 when the handpiece 5 is in its shipping configuration. Both theleading 25 and trailing 32 edges of the arm mount 21 are illustrated. Anarrowed portion 33 of the housing to which the tip 3 connects is alsoshown.

FIG. 12 is an exploded perspective view of the slider 7 and compressionarms 15, according to an embodiment of the invention. FIG. 12 shows aview of the slider 7 and compression components to reveal how the slider7 can move through the interior lumen 34 of the arm base 21 until thetrailing edge 32 of the arm base contacts the leading edge 35 of theslider base at the fully deployed configuration.

Cutting Element and Suction Cup Designs

FIG. 13 is a top perspective view of the cutting element 50, accordingto an embodiment of the invention. In the embodiment of FIG. 13, thecutting element 50 is an electrode that cuts the capsular membrane,though other designs are also possible (e.g., a sharp knife or multiplesharp knives or teeth). In use, electrical current can flow throughrigid lead 53A, through the 90 degree arc lead 51A, through electrodearc lead connection 52A, then into electrode ring 54. Half of thecurrent can flow clockwise and half can flow counter clockwise aroundthe ring 54 to connection 52B and into 90 degree arc lead 51B. Finally,the current flows out through rigid lead 53B. This design beneficiallyallows the heating of continuous ring 54 to uniformly heat and sever theportion of tissue. Since the current travels through connection 52A toring 54, and travels both directions along ring 54, the current isdistributed evenly on either side of the electrode to heat the tissuemore uniformly (as opposed to a ring through which current flows only inone direction from one point in the ring, which will heat the tissueless uniformly). This is just one example of an electrode configurationand current path. Multiple other designs can be used, as well.

The rigid leads 53A, 53B, anchoring tabs 56, 59, and 90 degree arc leads51A, 51B can be overmolded with elastomer (e.g., silicone, orpolyurethane). Gaps 55 that separate the rigid leads 53A, 53B can befilled with the overmolding elastomer and can prevent shorting ofcurrent between the rigid leads 53A, 53B. A lumen within the rigid leadscan be included for fluid flow and suction, so it typically is notfilled with elastomer. Fusible tethers 57, 58 can be designed as verythin ligaments that make the electrode robust for handling so that itretains its shape prior to overmolding. After overmolding, a prescribedsequence of electric currents can be applied to melt the tethers so thatthey become open circuits. The components of a larger cross section aretypically not affected by the currents needed to melt the small crosssection tethers 57, 58. This melting process can be performed at thefactory prior to shipping. The applied voltages, resulting currents, andresistances (before and after) can be monitored and recorded for qualitycontrol to ensure that each unit is properly fabricated. Optionally, theelectrode could be made without any tethers.

FIG. 14 is a top perspective view of the cutting element tethers 57, 58removed or made without tethers, according to an embodiment of theinvention. FIG. 14 shows the electrode with the tethers 57, 58 blown,leaving nonconducting gaps 57 x, 58 x.

FIG. 15 is a bottom perspective view of the suction cup 2, according toan embodiment of the invention. The suction cup 2 has a roof 66 and anopening 60 in the center. The suction cup 2 also has an interior channel61 that is bounded on either side by inner diameter (ID) wall 67 andouter diameter (OD) wall 68. The electrode ring 54 is positioned on theother side of OD wall 68.

When the suction cup 2 confronts the lens capsule 104 and suction isapplied through lumen 62, the pressure in the channel 61 of the suctioncup 2 can decrease. The lumen 62 connects through stem 63, through thedevice 1, and through hose barb 10 to the suction mechanism for applyingsuction. The outer diameter (OD) lip 64 and the inner diameter (ID) lip65 of the suction cup 2 can be pulled against the capsular membrane 104to form a low leakage seal so that the channel 61 pressure can bedecreased further to a predetermined value. The suction can also providea vacuum seal against the tissue. The suction can further pull portionsof the tissue up into the suction cup 2 for securing the suction cup 2against the tissue or for permitting severing of the tissue using thecutting element. The applied suction force can stretch the capsularmembrane over the edge of the cutting element to create a state of hightensile stress exactly on the circle where cutting is desired. Suctioncan also be used to retain the cut portion of tissue inside the device 1during removal. Since the cutting element is built-in directly to thedevice 1 that also provides the suction capabilities, the device 1 canbe used in a one-step procedure for performing a capsulotomy.

The OD lip 64 of the suction cup 2 has a flared skirt design extendingfrom the edge around the outer periphery of the suction cup 2. Theflared skirt allows the suction cup 2 to rest with low force against thecurved surface of the capsule 104 and allows the suction cup 2 to bevacuum sealed against the capsule 104 for the cutting procedure.

FIG. 16 is a cross-sectional bottom perspective view of the suction cup,according to an embodiment of the invention. The anchoring tabs 56 ofthe cutting element 50 are embedded in the overmolded elastomer. Therigid lead 53B is shown inside stem 63 of the suction cup 2. The lead53B is in electrical connection with electrode ring 54. The lumen 62 ofthe stem 63 is connected to the channel 61 in the suction cup 2 forproviding the suction.

FIG. 17 is a cross-sectional side view of another design of the suctioncup 70 (e.g., midridge or dual channel suction cup design), according toan embodiment of the invention. FIG. 17 shows the exposed electrode ring54 held by a supporting elastomer ridge 71 located in the middle of thechannel 61. This creates two suction channels 73, 72 so the capsularmembrane 104 can be stretched forcibly over the edge of electrode 54.

FIG. 18 is a top perspective view of another design of the cuttingelement 200, according to an embodiment of the invention. In use,current can flow from rigid lead 53A through connecting lead 203A andinto electrode ring 201. A fraction of the current can proceed aroundring 201, and the remaining fraction can go through gap material 204, toconnecting lead 203B. The fraction that flows through gap 204 can bezero if the material there is not conductive. But if the gap issufficiently small, the cutting action of the heat from electricaldischarge can be designed to bridge the gap so that the entire circle ofthe capsular membrane patch is cut. If the gap material is conductive,gap 204 can be designed (by having proper length width and thickness) toyield the same power dissipation per millimeter of circumferentiallength as occurs around ring 201 to achieve uniform heating and cuttingaction for the full circle. Example constructions can includeelectroformed nickel or steel for rigid leads 53A and 53B and gap 204.Electrode ring 201 can be electroformed gold or nickel, or etchedstainless steel. Anchoring tabs 202 are also shown in FIG. 18, similarto the tabs 56 shown in FIG. 14. In the embodiments of FIGS. 13, 15, and18, the cutting element is a circular cutting element mounted to theunderside of the suction cup. However, the cutting element can takeother shapes (e.g., elliptical, square, rectangular, irregular, andother shapes) for different types of surgical procedures where adifferently shaped incision in the tissue is desired. Similarly, thesuction cup can take on other shapes, as well.

Embodiments of device 1 can be used with electrical, mechanical, andcombined electro-mechanical cutting elements, though other designs couldbe used as well. The electrical cutting element functions as a resistor.A very short electrical pulse quickly heats up the element (e.g., togreater than 500° C., such as 600° C., 700° C., 800° C., 900° C., 1000°C., 1200° C., 1500° C., and so forth). In some embodiments, the heatingprocess lasts for a few microseconds (e.g., 10 microseconds or less),though heating times can differ in other embodiments (e.g., 1microsecond, 5 microseconds, 10 microseconds, 20 microseconds, 1millisecond, 5 milliseconds, etc.). The duration of the electricaldischarge is too short for heat to travel more than a few microns byconduction from the cutting element, so for a few microseconds the thinlayer of water that is trapped between the capsule and the cuttingelement absorbs the energy of the discharge and forms steam. The steamexpands rapidly at high pressure and increases the tensile stress in thecapsule enough to tear it. Since the electrical current is applied foronly a few microseconds, tissue is not burned as it is withelectrocautery instruments, and so the device 1 avoids the risksassociated with burning tissue in a patient's eye, with possiblecollateral damage to nearby tissue, with lengthy application of heat,and other problems. In addition, the electrical cutting element ofdevice 1 completes the severing of the tissue to free the severed piecefrom the capsule 104, unlike electrocautery devices that often requiretweezers to remove the severed piece. Further, in some embodiments, thecutting element has a mass of 0.35 milligrams or less, so bulky heatingelements are not required as are commonly found with electrocauteryinstruments.

Where the cutting element is mechanical, the element has one or moreultrasharp microteeth (or other tissue-severing knife or mechanism) thatpierce the capsule as the force of suction pulls the membrane past theteeth to sever the circular patch. Mechanical knife devices used in thepast for performing capsulotomies use the knife to stretch the tissue toprovide enough force against the cutting edge. In contrast, in thisdevice, the reaction force needed for cutting with the mechanicalcutting element of device 1 comes from suction supplied by the device.The suction pulls the tissue perpendicularly onto the cutting edge, sothere is no lateral distortion away from where the cut is supposed togo, and precision microcuts can be reproducibly made. In addition, acomplete cut can be made with the cutting element, as opposed to themultiple passes that are frequently required with microknives used inthe past. The cutting element can be a continuous ring similar to thoseshown in FIGS. 13, 14, and 18, or can be a non-continuous ring.

Where the cutting element is a combined electro-mechanical cuttingelement, it has one microtooth (or optionally, more than one) or othertissue severing mechanism that produces an initial tear in the capsule.The tear is propagated using the electrical cutting element design forapplying a short electrical pulse, as explained above. The tear can bepropagated to complete the capsulotomy by a lower steam pressure thanwould be required for an intact capsule.

FIG. 19 is an exploded top perspective view of another design 80 of thesuction cup and the cutting element involving dual tubing, according toan embodiment of the invention. The design is shown both assembled anddisassembled. The FIG. 19 design 80 includes two pieces of tubing 86A,86B (e.g., stainless steel tubing) that are assembled in rigid polymerstem 84. The shaped ends 87 of tubes 86A, 86B are joined to electrode85, and overmolded with elastomer 81 to form suction cup 82 with stem 83to hold on to the tubing. Other geometries can include two concentricconducting tubes separated by an insulating layer, one tube and anadjacent wire insulated from each other, a nonconducting tube with twoadjacent wires, and so forth.

Other Microsurgery/Capsulotomy Device Designs

FIG. 20 is a top perspective view of another design of themicrosurgery/capsulotomy device 90 with the suction cup stowed,according to an embodiment of the invention. In FIG. 20, the device 90is in a stowed (or as-shipped) configuration with the suction cup 99protected within the device. This design is an external compressionmechanism handpiece design 90. The manipulation mechanism includes apiston 97 for translating the suction cup 99 from the device 90 and thecompression mechanism includes an external slidable ring/member 94 andthe compression arms 93 that are attached to a housing of the handpiece95. The slidable ring 94 is slidably attached to the handpiece 95 forsliding distally, toward the suction cup 99, and over the compressionarms 93 positioned on either side of the suction cup 99, pressing thetips 92 of the arms 93 together to compress the suction cup 99.

The suction cup 99 is further attached to a stem 199 that connects to asliding element within the device 90, which is connected to the piston97. The piston 97 is manipulated or pressed distally toward to suctioncup 99 to distally push the sliding element inside the device 90. Thismoves the stem 199 and suction cup 99 distally. The tip of the device 90includes two insertion fingers 91 (e.g., two lips that can be designedto be compliant) disposed at the tip of the handpiece for maintainingthe compressed suction cup in a flattened position as it is translatedout of the tip and to the tissue. In the embodiment of FIG. 20, thefingers 91 are sloped inward toward each other at the tip and arepressed together to form a wedge for sliding cleanly through theincision. The fingers 91 are configured to separate with pressure fromthe suction cup 99 advancement out of the handpiece 95. In the FIG. 20embodiment, the distal portion of the handpiece 94 is designed to havean upper flat portion and a lower flat portion that also help to holdthe suction cup 99 flat during deployment. The compression arms 93 aredesigned to slide between the upper and lower portions to compress thesuction cup 99 laterally. The hose connector 96 for providing suction tothe suction cup 99 is just visible in FIG. 20.

FIG. 21 is a bottom perspective view of the FIG. 20 design of themicrosurgery/capsulotomy device 90 with the suction cup 99 deployed,according to an embodiment of the invention. This figure betterillustrates the hose connector 96 that provides fluid and/or suction tothe suction cup (in a manner similar to that done in device 1) andelectrical connectors 98 that provide electrical current into the deviceand to a cutting element in the suction cup 99. The cutting element indevice 90 can be any of the cutting element designs described above. Forcutting elements that are not electrical in either devices 1 or 90, theelectrical connections and components may not be included in the design.

FIG. 22 is a top perspective view of the FIGS. 20, 21 design of themicrosurgery/capsulotomy device 90 with the suction cup 99 deployed,according to an embodiment of the invention. Upon deployment, thesuction cup 99 expanded back into its prior shape.

Surgical Procedure

FIG. 23 is a flow chart illustrating various preparatory steps for themicrosurgery/capsulotomy procedure, including a procedure that can beused with devices 1, 90, according to an embodiment of the invention.For FIGS. 23-25, the steps can vary across different procedures,including having additional or different steps than those shown, and thesteps can occur in different orders.

In FIG. 23, the surgeon/user connects or plugs in 2300 a device into aconnector to the nondisposable controlling system. The connectorprovides for the transmission of suction to the lumen of the device andelectrical current to the electrode of the device (i.e., where thecutting element is an electrode). A computer associated with thecontrolling system checks electrical and fluidic viability of thedevice. During this self-checking, the computer can measure 2302 theelectrical resistance of the electrode. If outside the allowed range fora good or fully functional/acceptable device, an alarm or othernotification mechanism (e.g., lights, beeping, vibration, text displayedon screen, etc.) notifies 2304 user to replace it, and computer will notexecute the surgical program until the problem is remedied. If theresistance is good and within the acceptable range, the operation mayproceed. The computer continues to make resistance measurements 2302 atpredetermined intervals (e.g., once per second). Similarly if anymeasurement indicates a problem, an alarm can alert 2304 the user andthe procedure can be halted. Note that a unit that has previously beenused in a surgical procedure will have a high resistance above theallowed range, so the computer prevents the accidental use of used ordamaged units.

Also during the self-checking procedure, the computer can measure 2306air flow rate versus pressure (i.e., clean dry filtered air can be blownout through the suction cup for this test). If not within the allowedrange, an alarm or other notification system notifies 2308 the user toreplace the device or otherwise correct the problem, and the computerwill not execute the surgical program until it is corrected. This isdone at least once at plug in, before the user has a chance to move onto any further steps. Once the preparatory steps are completed 2310, thedevice is ready for use.

FIG. 24 is a flow chart illustrating steps for themicrosurgery/capsulotomy procedure, according to an embodiment of theinvention. The user can inject 2400 lubricant (e.g., viscoelastic) ontothe suction cup for lubrication. Viscoelastic is commonly used incataract surgery to keep the anterior chamber of the eye inflated. Theuser compresses 2402 the suction cup by manipulating the device (e.g.,via the knob 8 or via the slidable ring 94). For device 1, the userperforms step 2402 by pushing the knob 8 along slot 9 to translate thesuction cup/compression mechanism ensemble up to the entrance of theinsertion tip 3, which moves the compression arms distally to press thearms against internal walls of the handpiece 5, moving the arms inwardtoward each other to compress the suction cup 2. For device 90, the userperforms step 2402 by sliding the slidable ring 94 distally over thecompression arms 93, pressing the arms 93 together to compress thesuction cup 99. The user can then further manipulate the device totranslate 2404 the lubricated and compressed suction cup into theinsertion tip of the device. For device 1, the user performs step 2404by further pushing knob 8 along slot 9 to move the suction cup 2distally into the tip 3. For device 90, the user performs step 2404 bypushing the piston 97 to move the suction cup 99 to the tip of thedevice.

The user moves/inserts 2406 the tip of the capsulotomy device through anincision in the tissue (e.g., the cornea of the eye). In someembodiments of the procedure, one or both of steps 2402 and 2404 occurbefore step 2406, so that the suction cup is compressed 2402 and/ortranslated 2404 into the insertion tip after insertion 2406 of the tipthrough the incision. The user deploys 2408 the compressed suction cupout through the tip of the handpiece to the tissue (e.g., into theanterior chamber to the lens capsule). The suction cup expands insidethe tissue (e.g., into the anterior chamber of the eye, past the cornea)into a cutting position (e.g., on the lens capsule). For devices, suchas device 1 and 90, the suction cup is mounted to a sliding element, sodeploying the compressed suction cup includes translating the slidingelement distally to move the suction cup within the handpiece, outthrough the tip and to the tissue. The user can then position 2410 thesuction cup by centering it over the tissue, and orient pitch and rollto seat it against the tissue (e.g., the lens capsule). The useractivates 2412 the suction to pull the suction cup against tissue, andthereby force the cutting element against the tissue (e.g., lenscapsular membrane).

The user can verify 2414 that the desired low leakage suction seal hasbeen established by moving the device horizontally or vertically (e.g.,by 0.25 mm) to make sure that the lens moves with it. The user canfurther perform one or more system checks for the suction cup seal. Thecontrolling computer can also verify that a low leakage seal has beenestablished by reading 2416 the flow sensor that should show little orno liquid flow in the suction line. The pressure sensor is alsomonitored 2418, since a threshold low pressure will typically be reachedin the suction line before the computer will proceed with the surgicalprogram. If either the reading 2416 or the monitoring 2418 show aproblem, the user can be notified, 2417, 2419 to correct the problem.The user then proceeds to the begin usage of the device for cutting oftissue with the cutting element. Where there is no electrical cuttingelement on the device, the user proceeds to non-electrically cut 2420the tissue. For example, the user can cut 2420 the tissue via thesuction applied to the suction cup to pull the tissue against themechanical cutting element (e.g., sharp blade(s)). Where there is anelectrical cutting element on the device, the procedure proceeds to FIG.25 for electrical cutting steps.

FIG. 25 is a flow chart illustrating a continuation of the steps for themicrosurgery/capsulotomy procedure, according to an embodiment of theinvention. The user requests 2500 the electrical discharge for cutting(e.g., via any type of user interface, such as by pressing a button,verbally with voice recognition software, etc.). The controllingcomputer does one last measurement 2502 of the electrode resistance,pressure and flow sensors. If all conditions are in range, the cuttingoccurs 2503 and the discharge is delivered. If not, the user is notified2504 and can take action to remedy any problems. The electricaldischarge for surgery may include several stages, such as thefollowing: 1) degas (e.g., electrode held at 60° C. to 99° C.), 2)thermal tangling (e.g., electrode held at 60° C. to 99° C.), 3) cuttingdischarge (e.g., electrode heated to 200° C. to 1000° C.), and/or 4)electrode modifying spike (e.g., brief current spike to melt one or moreelectrode components). After discharge, the system checks 2506 theresistance of the electrode. If the resistance is outside the expectedpost-discharge range, an alarm notifies 2508 the user that an anomalyoccurred and to execute appropriate diagnostic procedures. Otherwise,the user can proceed to the next step.

The user then reduces 2510 suction applied to the suction cup. Thesuction vacuum is reduced to allow the user to pull the suction cup awayfrom the tissue. If the excised patch of membrane has been sucked intothe lumen of the stem, then the suction can be completely turned off.Otherwise some suction can be maintained to the level needed to ensurethat the patch is held and removed from the eye along with the device.The user then removes 2512 the device from the tissue (e.g., from theeye).

Device Fabrication

A variety of different mechanisms can be used in fabricating thecomponents of the device. For example, the components of the handpiececan be made by injection molding of plastic. The suction cup can be madeby overmolding a suitable elastomer (e.g., silicone, or polyurethane)over the electrode and stem, which have been positioned in the mold,though other materials can be used as well. The suction cup is designedto be collapsible to a small cross section so that it can be insertedthrough a corneal incision (e.g., an incision of less than 2 to 3 mm inlength) but then can rapidly return to its circular shape afterdeployment. The thinner the walls are, the stiffer (higher durometer)the material can be. The size for the suction cup can range from about4.5 mm to about 7 mm in diameter, while the height would commonly rangefrom about 0.5 mm to about 1.5 mm. The suction cup and overall devicedesign and size ranges can vary to match the surgical procedure beingconducted.

The cutting element can be made from various materials. The metalliccomponents of the electrode can be made by electroforming of suitablemetals such as nickel, gold, steel, copper, platinum, iridium, etc.Connections between the electrode and leads in the stem can be made byelectroplating, or welding. Typically, for electrical cutting elements,the material for the cutting element is electrically conductive, and formechanical cutting elements, the material is hard enough to pierce themembrane. For both electrical and mechanical cutting elements, thematerial is also generally elastic enough to return to its prior shapeafter being squeezed to get through the tissue incision, or soft enoughto be pushed back into circular shape by the polymeric support ringand/or by the suction cup in which it is mounted. For example, for anelectrical cutting element, the materials can include those made byphotochemical etching, such as spring steel, stainless steel, titaniumnickel alloy, graphite, nitinol (NiTi alloy “memory metal”), nickel,nickel-chrome alloy, tungsten, molybdenum, or any other material thatwill allow the element to return to its prior shape. Other materials forelectrical cutting elements include electrically conductive elastomers,including elastomers (e.g., silicone or polyurethane) mixed withappropriately shaped conductive particles (e.g., silver, gold, graphite,copper, etc) that can establish contact with each other and continue tobe in contact with each other for the duration of the electricaldischarge. An additional example of a material for electrical cuttingelements includes a compliant mesh of very fine wires (e.g., diameter ofabout 1 or 2 microns) that can be anchored in the elastomeric supportring to make the conductive element. As a further example, materials canbe used for electrical cutting elements that are made by sputteringmetal onto a polymeric support, such as high conductivity metals (e.g.,gold, aluminum, copper, etc.), which can be used to make very thin(e.g., 1 micron) elements with resistance within the usable range (e.g.,1 to 10 ohms) deposited by RF plasma sputtering.

Materials used for mechanical cutting elements can includephotochemically etched metal (e.g., stainless steel), or a relativelyhard plastic (e.g., phenolic), among others. Discrete micro teeth couldbe etched from single crystal silicon. Photochemical etching can used tomake cutting elements that have a thickness of, for example, 25 microns,or 12.5 microns, or 5 microns, and so forth.

The above description is included to illustrate the operation of theembodiments and is not meant to limit the scope of the invention. Thescope of the invention is to be limited only by the following claims.From the above discussion, many variations will be apparent to oneskilled in the relevant art that would yet be encompassed by the spiritand scope of the invention. As used herein any reference to “oneembodiment” or “an embodiment” means that a particular element, feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment. The appearances of the phrase“in one embodiment” in various places in the specification are notnecessarily all referring to the same embodiment.

I claim:
 1. A capsulotomy device for accessing a lens capsule through acornea of an eye, the device comprising: a handpiece; a suction cupmounted to a stem that is mounted to the handpiece; a cutting elementmounted to the suction cup, the cutting element configured for cutting aportion of the lens capsule; one or more electrical leads connected tothe cutting element to deliver at least one electrical pulse to thecutting element to heat the cutting element for cutting the portion ofthe lens capsule; a compression device comprising at least one arm thatis slidable relative to the suction cup and handpiece for distaltranslation to cause compression of the suction cup and the cuttingelement for deployment of the suction cup and cutting element through anincision in the cornea and into an anterior chamber of the eye, thesuction cup and cutting element configured to expand inside the anteriorchamber into a cutting position on the lens capsule for cutting theportion of the lens capsule; and a manipulation device associated withthe compression device, the manipulation device slidable along a slot inthe handpiece for translating the compression device distally to causethe compression of the suction cup and cutting element.
 2. The device ofclaim 1, wherein manipulation device comprises a control connectedthrough a slot in the handpiece to the compression device, the controlconfigured to slide the compression device toward the suction cup toengage the suction cup to cause the compression by changing the shape ofthe suction cup and cutting element for insertion through the incision.3. The device of claim 2, wherein the manipulation device is connectedto a base of the at least one arm of the compression device, the basepositioned within the handpiece for distal translation within thehandpiece.
 4. The device claim 1, wherein the cutting element is anelectrical cutting element mounted to an underside of the suction cup,and wherein the cutting element is configured to be heated by passage ofelectrical current traveling in the cutting element to uniformly excisethe portion of the lens capsule.
 5. The device of claim 1, furthercomprising one or more suction elements connected to the suction cup,the one or more suction elements for applying suction to the suction cupto secure the suction cup against the lens capsule.
 6. The device ofclaim 1, wherein the cutting element is an electrical cutting elementthat functions as a resistor, and wherein the at least one electricalpulse heats the cutting element to excise a patch of tissue from thelens capsule for removal of the patch from the eye.
 7. The device ofclaim 1, wherein a total duration of the at least one electrical pulseis 500 milliseconds or less.
 8. A capsulotomy device for accessing alens capsule through a cornea of an eye, the device comprising: ahandpiece; a suction cup mounted to a stem that is mounted to thehandpiece; a cutting element mounted to the suction cup for cutting aportion of the lens capsule; a compression device comprising at leastone arm that is slidable relative to the suction cup and handpiece fordistal translation to cause a change in shape of the suction cup and thecutting element for deployment of the suction cup and cutting elementthrough an incision in the cornea and into an anterior chamber of theeye, the suction cup and cutting element configured to expand inside theanterior chamber into a cutting position on the lens capsule for cuttingthe portion of the lens capsule; and a manipulation device connectedthrough a slot in the handpiece to the compression device, themanipulation device configured to slide the compression device towardthe suction cup to engage the suction cup to cause the change in shapeof the suction cup and cutting element for insertion through theincision.
 9. The device of claim 8, wherein the manipulation device isconnected to a base of the at least one arm of the compression device,the base positioned within the handpiece for distal translation withinthe handpiece.
 10. The device claim 8, wherein the cutting element is anelectrical cutting element mounted to an underside of the suction cup,and wherein the cutting element is configured to be heated by passage ofelectrical current traveling in the cutting element to uniformly excisethe portion of the lens capsule.
 11. The device of claim 8, furthercomprising one or more suction elements connected to the suction cup andrunning within the stem and the handpiece, the one or more suctionelements for applying suction to the suction cup to secure the suctioncup against the lens capsule.
 12. The device of claim 8, wherein thecutting element is an electrical cutting element, and wherein the devicefurther comprises one or more electrical leads connected to the cuttingelement to deliver at least one electrical pulse to the cutting elementto heat the cutting element for cutting the portion of the lens capsule.13. The device of claim 12, wherein a total duration of the at least oneelectrical pulse is 500 milliseconds or less.
 14. The device of claim 8,wherein the suction cup forms a ring around a central area or opening.15. The device of claim 8, wherein the compression device is configuredfor distal translation relative to the handpiece and suction cup tocause extension of and narrowing of the suction cup and the cuttingelement for insertion through the incision in the cornea.
 16. Acapsulotomy device for accessing a lens capsule through a cornea of aneye, the device comprising: a handpiece; a cutting element mounted to astem that is mounted to the handpiece, the cutting element for cutting aportion of the lens capsule; one or more electrical leads connected tothe cutting element to deliver at least one electrical pulse to thecutting element to heat the cutting element for cutting the portion ofthe lens capsule; a compression device comprising at least one arm thatis slidable relative to the handpiece for distal translation to cause achange in shape of the cutting element before moving the cutting elementthrough an incision in the cornea of the eye, the cutting elementconfigured to expand inside the anterior chamber into a cutting positionon the lens capsule for cutting the portion of the lens capsule; and amanipulation device connected through the handpiece to the compressiondevice, the manipulation device configured to slide the compressiondevice relative to the cutting element to cause the change in shape ofthe cutting element for moving the cutting element through the incision.17. The device claim 16, wherein the cutting element is a continuouscircular cutting element configured to be heated by passage ofelectrical current traveling in the cutting element to uniformly excisethe portion of the lens capsule.
 18. The device of claim 16, furthercomprising a suction cup to which the cutting element is mounted and oneor more suction elements connected to the suction cup for applyingsuction to the suction cup to secure the suction cup against the lenscapsule.
 19. The device claim 18, wherein the cutting element is mountedto an underside of the suction cup.
 20. The device of claim 16, whereinthe at least one pulse comprises a plurality of pulses, and a totalduration of the pulses is 500 milliseconds or less.
 21. The device ofclaim 16, wherein the manipulation device is connected to a base of theat least one arm of the compression device, the base positioned withinthe handpiece for distal translation within the handpiece.